1. Field of the Invention
The present invention relates to a heat-dissipating device, and in particular to a two-layer wind-guiding shroud.
2. Description of Prior Art
With the rapid advancement of information technology, electronic elements in a server such as a central processing unit (CPU), a graphic processing unit (GPU) or the like has a greater speed for processing data. On the other hand, the volume of each electronic element is required to be made compact, and the electronic elements are densely arranged per unit area. Further, the amount of heat generated during the operation of the electronic elements increases to a greater extent, so that the generated heat will be accumulated in the electronic elements. As a result, the electronic elements may be overheated to deteriorate the stability and efficiency of the server. Thus, a heat-dissipating device has to be installed in the server to dissipate the heat generated by the electronic elements, thereby lowering the temperature of the electronic elements.
The conventional heat-dissipating device (such as a heat sink) is fixed onto a heat-generating element to dissipate the heat generated thereby. However, such a heat dissipation is achieved by air convection in the heat sink together with the heat radiation, so that the heat-dissipating efficiency is insufficient. Accordingly, besides the heat sink installed in the server, at least one fan and a wind-guiding shroud are provided. As shown in FIGS. 1 and 2, the conventional wind-guiding shroud 10 comprises a shroud 20. One side of the shroud 20 has a fixing portion 30 and a wind-guiding channel 40 formed inside the shroud 20. A fan is provided at the fixing portion 30, so that the airflow generated by the fan can flow to the heat sink via the wind-guiding channel 40, thereby generating a compulsory airflow to lower the temperature of the heat-generating element quickly.
However, in the wind-guiding channel 40 of the wind-guiding shroud 10, the wind-entering direction and the wind-exiting direction are located in the same axial line. Thus, the fan can only blow a linear airflow. As a result, the area of air convection generated by the fan is so limited that the heat-dissipating efficiency is smaller than the heat-generating rate of the heat-generating element, which negatively affects the operation of the electronic device. In order to solve this problem, a plurality of fans and the wind-guiding shroud 10 are usually arranged toward the respective electronic elements to enhance the heat-dissipating efficiency. Although the above-mentioned heat-dissipating device can dissipate the heat in the server, the plurality of fans and the wind-guiding shroud 10 inevitably increase the cost of the whole device. Further, the size and area of the thus-formed server are larger with a complicated structure. Moreover, the fans generate vibration during their operation, which may affect the normal function of hard disks and thus deteriorates the performance of the server.
In view of the above, the present Inventor proposes a novel and reasonable structure based on his expert knowledge and deliberate researches.